Question

The compound used in the manufacture of terylene is (a) ethylene (b) vinyl chloride (c) ethylene glycol (d) adipic acid

Short answer

(c) ethylene glycol

Step-by-step solution

Recall Terylene Composition

Terylene, also known as Dacron or PET, is a type of polyester. It is synthesized from the reaction between ethylene glycol and terephthalic acid. Understanding the components of Terylene helps in identifying the correct compound used in its manufacture.

Identify Compatible Compounds

Among the options given, recognize that ethylene glycol is a crucial component in the synthesis of Terylene. Ethylene glycol (option c) is an alcohol that reacts with terephthalic acid to form polyester fiber, known commercially as Terylene.

Compare with Other Options

Check the other options to verify compatibility: - Ethylene (option a) is an alkene used to make ethylene-based polymers, not Terylene. - Vinyl chloride (option b) is used to produce polyvinyl chloride (PVC), not Terylene. - Adipic acid (option d) is used to make nylon, not Terylene. Only ethylene glycol matches the requirements for Terylene synthesis.

Conclude with Correct Answer

Based on the understanding of the chemical compounds and their roles in Terylene production, conclude that the compound used in manufacturing Terylene is ethylene glycol (c).

Key concepts

Understanding Ethylene Glycol

Ethylene glycol is an essential chemical in the manufacture of Terylene. This compound, a type of alcohol, possesses the formula \( \text{C}_2\text{H}_6\text{O}_2 \), which places it in the category of diols. These molecules have two hydroxyl groups. Ethylene glycol is prized in the chemical industry due to its properties and versatile applications, notably in antifreeze and as a precursor to various polymers.
In the context of Terylene, ethylene glycol plays a vital role by reacting with terephthalic acid to form long chains of polyester. These chains form Terylene, a polyester known for its strength and resilience.
This chemical interaction involves forming ester linkages, a crucial step in creating fibers suitable for textiles and packaging. In brief, ethylene glycol isn't just a raw material; it is the backbone on which much of the Terylene structure relies.

The Process of Polyester Synthesis

Polyester synthesis, particularly for Terylene, involves a chemical reaction known as polycondensation. This process is where small molecules, or monomers, like ethylene glycol and terephthalic acid, combine to form larger, more complex macromolecules.

• **Step One: Esterification** - Here, ethylene glycol reacts with terephthalic acid to form a monomer with ester groups.
• **Step Two: Polycondensation** - The monomers undergo a condensation reaction to form long polymer chains, releasing small molecules like water as byproducts.

During polyester synthesis, precise conditions are maintained to ensure the length and strength of the polymer chains. The resulting polyester, also called PET, exhibits desirable properties such as flexibility, durability, and resistance to many chemical agents.
Polyester synthesis is pivotal in producing materials like textiles, plastic bottles, and food packaging, highlighting its extensive commercial and industrial applications.

Role and Importance of Terephthalic Acid

Terephthalic acid, essential in the production of Terylene, is an aromatic carboxylic acid. This compound has the formula \( \text{C}_8\text{H}_6\text{O}_4 \) and plays a significant role in polyester production.

• **Key Component** - In the synthesis process, terephthalic acid provides the aromatic rings, imparting strength and thermal stability to the polyester fibers.
• **Reactivity** - Its carboxyl groups react with the hydroxyl groups of ethylene glycol, forming ester bonds in the polyester synthesis process.

Terephthalic acid's significance stems from its ability to undergo polymerization with ethylene glycol, leading to the formation of strong and durable polyester chains. These chains are not only integral to making Terylene but also form the basis of a host of everyday products, from clothing to containers.
The integrity of terephthalic acid as a reactant ensures the quality and performance of the final polyester product, making it indispensable in the field of materials science.